Abnormal adrenocortical regulation and decreased central noradrenergic activity and altered receptor sensitivity have been independently described in endogenous depression. Norepinephrine has been implicated as the neurotransmitter mediating inhibitory feedback of the hypothalamic-pituitary-adrenal axis. This clinical research study investigates the relationship of peripheral and central noradrenergic activity and clinical symptomatology to the abnormal cortisol secretion and dexamethasone suppression response reported in patients with endogenous depression. Subjects will be a carefully selected group of psychiatric inpatients with endogenous Major Depressive Disorder diagnosed by RDC criteria based on SADS inteview and rated on the HDRS and BDI. Adrenocortical function will be evaluated at baseline and following the dexamethasone suppression test using serial plasma cortisol and 24-hour urinary free cortisol measures. Noradrenergic activity will be evaluated peripherally by measurement of basal and stimulated plasma norepinephrine, and centrally by measurement of the norepinephrine metabolite, urinary MHPG.